PCAL9554BPWJ

I/o Expanders Overview

The PCAL9554BPWJ is an 8-bit I/O expander from NXP Semiconductors, packaged in a TSSOP16 format. It operates on a supply voltage range of 1.65 V to 5.5 V and supports I2C-bus/SMBus interfaces with a maximum clock frequency of 400 kHz. The device features an open-drain interrupt output, weak pull-ups, and Agile I/O capabilities including programmable drive strength and latchable inputs. It functions within an ambient temperature range of -40 °C to +85 °C.

I/o Expanders Feature Summary

• Agile I/O functionality enabling programmable output drive strength, input latching, and configurable pull-up/pull-down resistors.
• Open-drain active LOW interrupt output (INT) that signals state changes to the system master without continuous bus polling.
• Internal power-on reset ensures registers initialize to default states upon power application, preventing spurious outputs.

I/o Expanders Applications

• ACPI power switches
• Sensor interface circuits
• Push button scanning systems
• LED driving applications

I/o Expanders Procurement Notes

Verify the specific ordering suffix 'J' corresponds to the reel packing method defined in the official datasheet. Confirm the component type matches the PCAL9554B variant rather than the PCAL9554C variant due to distinct fixed I2C addresses. Ensure the TSSOP16 package designation aligns with the required board layout constraints.

I/o Expanders Selection Notes

Select this component when pin-to-pin compatibility with PCA9554 devices is required alongside enhanced Agile I/O features. Consider the PCAL9554B fixed address if multiple devices share the same bus to prevent conflicts. Evaluate the 25 mA sink capability for direct LED driving needs against the low standby current consumption requirements.

I/o Expanders Part Context

This part belongs to the PCAL9554 series, which serves as a low-power enhancement over the legacy PCA9554 family. The PCAL9554B variant specifically targets replacements for the PCA9554, offering software backward compatibility while introducing advanced configuration options like interrupt masking and polarity inversion.

I/o Expanders Replacement Considerations

PCAL9554BS,128

I/o Expanders FAQ

How does the PCAL9554B differ from the PCAL9554C?

The only difference between the PCAL9554B and PCAL9554C is their fixed I2C-bus address, allowing up to 16 devices of the same type to operate on a single bus without address conflicts.

What is the function of the Agile I/O feature?

Agile I/O provides enhanced control including programmable output drive strength, latchable inputs, and selectable pull-up/pull-down resistors to optimize performance for specific circuit conditions.

How is the interrupt output cleared?

The open-drain interrupt output is cleared by reading the Input Port register or by changing the port data back to its original setting before the read operation.